Gbabb, (and all)
The 'hover' was a pre-RPM#30 move that involved pulling the butt to "hover" over the back of the saddle and dropping the chest in order to work the Gluteals and the hamstrings more. It also added great variety to tracks 3 & 7 (rather than just having Standing climb, seated climb, power training and standing attack). However, it is my understanding that the hover position was abandoned because it was found too place too much pressure on the lower back, especially when participants do what participants do best; over-exaggerate movements.
However, I think a lot of people complained when it was taken out because a certain degree of variety in the climbing tracks was lost. Therefore Dan and Glenn compromised, creating a new move called the pullback climb, similar to the Hover but without pulling the but back as far (only to the middle of the saddle) and keeping the chest elevated. As a result, Variety in tracks 3 & 7 could be achieved without risking injury to the lumbar spine.... everyone's happy!
All of this was in the RPM 39 DVD educational session and (to a briefer extent) in the RPM 39 choreography notes.
Just a tip/observation: When introducing the new move in RPM 39 (between tracks 6 & 7) I find it better to not even tell the back story or mention the past hover position to participants. Even though it shows your knowledge, there's two reasons behind this for me: 1) It takes to long; I want to have the whole explanation done in under 30 seconds so my participants dont get too much rest to lose training benefits.... 2) Don't even put the hover position in their heads. Veteran participants may get confused and think you mean to do the hover, or if you demonstrate the hover and the pullback climb to show the difference, they may mix them up and do the hover, thinking they are doing the PC.
I just say tell them there is a new move, name it, demonstrate it, and then get into the mountains.
Hope all this makes sense.
Cheers,
Colby